N.H. Code Admin. R. Plu 102.07
“Water treatment system” means “water treatment system” as defined in RSA 329-A:2, VI, namely, "any apparatus for treating or processing water to modify, enhance, or improve its quality or to meet a specific water quality need, desire, or standard, and the pipes, fittings, and other components servicing such apparatus."
Source. #8980, eff 9-20-07